[HICN-488] Adding lock to vapi calls and manage vapi_connect in order to connect only once.

- Added library to hicn-plugin called safe_vapi that takes care of handling concurrent calls to the vapi.
- Removed dependency of libhicnctrl from libtransport and added dependency to safe_vapi.
- Added dependency to safe_vapi on libhicnctrl

Change-Id: Ie49e8319f64a50e7ed6a56e041db977c3b184cc5
Signed-off-by: Alberto Compagno <acompagn+fdio@cisco.com>

3 files changed, 164 insertions, 0 deletions

diff --git a/hicn-plugin/vapi/CMakeLists.txt b/hicn-plugin/vapi/CMakeLists.txt
new file mode 100644
index 000000000..00bcaf49f
--- /dev/null
+++ b/hicn-plugin/vapi/CMakeLists.txt
@@ -0,0 +1,70 @@
+# Copyright (c) 2019 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+
+set(SAFE_VAPI safe_vapi CACHE INTERNAL "" FORCE)
+set(SAFE_VAPI_SHARED ${SAFE_VAPI}.shared CACHE INTERNAL "" FORCE)
+set(SAFE_VAPI_STATIC ${SAFE_VAPI}.static CACHE INTERNAL "" FORCE)
+
+project(${SAFE_VAPI})
+
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
+    "${CMAKE_CURRENT_SOURCE_DIR}/../../cmake/Modules/"
+    "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules/"
+)
+
+include (Packaging)
+include (BuildMacros)
+
+# Dependencies
+
+find_package(Vpp REQUIRED)
+
+list(APPEND HEADER_FILES
+     ${CMAKE_CURRENT_SOURCE_DIR}/include/vapi/vapi_safe.h
+)
+
+list(APPEND SOURCE_FILES
+     ${CMAKE_CURRENT_SOURCE_DIR}/vapi_safe.c
+)
+
+set (LIBRARIES
+    ${VPP_LIBRARIES})
+
+list (APPEND INCLUDE_DIRS
+     ${VPP_INCLUDE_DIR}
+     ${CMAKE_CURRENT_SOURCE_DIR}/include)
+
+build_library(${SAFE_VAPI}
+    SHARED STATIC
+    SOURCES ${SOURCE_FILES} ${HEADER_FILES}
+    INSTALL_HEADERS ${HEADER_FILES}
+    LINK_LIBRARIES ${LIBRARIES}
+    COMPONENT ${HICN_PLUGIN}
+    INCLUDE_DIRS ${INCLUDE_DIRS}
+    INSTALL_ROOT_DIR /
+    DEFINITIONS ${COMPILER_DEFINITIONS}
+  )
+
+set(SAFE_VAPI_INCLUDE_DIRS
+  ${CMAKE_CURRENT_SOURCE_DIR}/include
+  "" CACHE INTERNAL
+  "" FORCE
+)
+
+set(SAFE_VAPI_LIBRARIES
+  ${SAFE_VAPI_SHARED}
+  "" CACHE INTERNAL
+  "" FORCE
+)
+
diff --git a/hicn-plugin/vapi/include/vapi/vapi_safe.h b/hicn-plugin/vapi/include/vapi/vapi_safe.h
new file mode 100644
index 000000000..df1114cde
--- /dev/null
+++ b/hicn-plugin/vapi/include/vapi/vapi_safe.h
@@ -0,0 +1,19 @@
+#ifndef VAPI_SAFE
+#include <vapi/vapi.h>
+#include <pthread.h>
+
+extern pthread_mutex_t *mutex;
+
+vapi_error_e vapi_connect_safe(vapi_ctx_t * vapi_ctx_ret, int async);
+
+vapi_error_e vapi_disconnect_safe();
+void vapi_lock();
+
+void vapi_unlock();
+
+#define VAPI_SAFE (NAME, res, ...)		\
+    vapi_lock();                                \
+    res = ## NAME (__ARGS__);			\
+    vapi_unlock();
+
+#endif //VAPI_SAFE
diff --git a/hicn-plugin/vapi/vapi_safe.c b/hicn-plugin/vapi/vapi_safe.c
new file mode 100644
index 000000000..c1d66c0ac
--- /dev/null
+++ b/hicn-plugin/vapi/vapi_safe.c
@@ -0,0 +1,75 @@
+#include <vapi/vapi_safe.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define APP_NAME "hicn_plugin"
+#define MAX_OUTSTANDING_REQUESTS 4
+#define RESPONSE_QUEUE_SIZE 2
+
+pthread_mutex_t *mutex = NULL;
+vapi_ctx_t g_vapi_ctx_instance = NULL;
+u32 count = 0;
+int lock = 0;
+
+vapi_error_e vapi_connect_safe(vapi_ctx_t *vapi_ctx_ret, int async) {
+  vapi_error_e rv  = VAPI_OK;
+
+  while (!__sync_bool_compare_and_swap(&lock, 0, 1));
+
+  if (!g_vapi_ctx_instance && !mutex)
+    {
+      rv = vapi_ctx_alloc(&g_vapi_ctx_instance);
+      if (rv != VAPI_OK)
+	goto err;
+
+      mutex = malloc(sizeof(pthread_mutex_t));
+      if (!mutex)
+	goto err_mutex_alloc;
+
+      if (pthread_mutex_init(mutex, NULL) != 0) {
+	printf("Mutex init failed\n");
+	goto err_mutex_init;
+      }
+    }
+
+  if (!count)
+    {
+      rv = vapi_connect(g_vapi_ctx_instance, APP_NAME, NULL,
+			MAX_OUTSTANDING_REQUESTS, RESPONSE_QUEUE_SIZE,
+			async ? VAPI_MODE_NONBLOCKING : VAPI_MODE_BLOCKING, true);
+
+      if (rv != VAPI_OK)
+	goto err_vapi;
+
+      count++;
+    }
+
+  *vapi_ctx_ret = g_vapi_ctx_instance;
+
+  while (!__sync_bool_compare_and_swap(&lock, 1, 0));
+  return rv;
+
+ err_vapi:
+  vapi_ctx_free(g_vapi_ctx_instance);
+ err_mutex_init:
+  free(mutex);
+ err_mutex_alloc:
+ err:
+  while (!__sync_bool_compare_and_swap(&lock, 1, 0));
+  return VAPI_ENOMEM;
+}
+
+vapi_error_e vapi_disconnect_safe() {
+  pthread_mutex_lock(mutex);
+  vapi_error_e rv = VAPI_OK;
+  pthread_mutex_unlock(mutex);
+  return rv;
+}
+
+void vapi_lock() {
+  pthread_mutex_lock(mutex);
+}
+
+void vapi_unlock() {
+  pthread_mutex_unlock(mutex);
+}